Rice Guanine Nucleotide Exchange Factors for Small GTPase OsRac1 Involved in Innate Immunity of Rice
Rice Guanine Nucleotide Exchange Factors for Small GTPase OsRac1 Involved in Innate Immunity of Rice
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DOI：
10.1007/978-1-4020-9500-9_18
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
T. Kawasaki;K. Imai;H. Wong;Y. Kawano;Keita Nishide;J. Okuda;K. Shimamoto
中科院分区：
文献类型：
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作者：
T. Kawasaki;K. Imai;H. Wong;Y. Kawano;Keita Nishide;J. Okuda;K. Shimamoto
OsRac 1是水稻诱导免疫应答的关键调控因子。OsRac 1的激活可诱导NADPH氧化酶介导的活性氧（ROS）产生、PR基因表达、抗菌物质产生和木质化，从而增强水稻对稻瘟病菌和黄单胞菌的抗性。OsRac 1功能的抑制抑制了由aaclentM诱导的过敏反应。米。因此，OsRac 1可能在R蛋白介导的抗性和基础抗性中发挥重要作用。然而，OsRac 1在免疫应答过程中如何被激活仍然未知。近年来，在植物中发现了一种新的Rac/Rop GTdR的鸟嘌呤核苷酸交换因子（GEF），称为PRONE型GEF。我们在水稻中发现了11个PRONE型RacGEFs，它们可能参与了OsRac 1在先天免疫应答中的调控。近年来，研究发现PRONE型GEF与水稻中类似R蛋白的受体样蛋白激酶和PAMPs受体Xa-21、Pi-d2、FLS 2和EFR相互作用，表明OsRacGEF可能通过激活OsRac 1来调节PAMPs和R蛋白介导的水稻抗病性。
Small GTPase OsRac1 is a key regulator for induction of immune responses in rice. Activation of OsRac1 induces NADPH oxidase-mediated reactive oxygen species (ROS) production, PR gene expression, production of antimicrobial compounds, and lignification, which result in enhanced resistance toMagnaporthe oryzaeandXanthomonas oryzae. Inhibition of OsRac1 function suppresses the hypersensitive response induced by avirulentM. oryzae. Thus, it is likely that OsRac1 plays important roles in R protein-mediated resistance and basal resistance. However, how OsRac1 is activated during immune response remains unknown. Recently, a new type of guanine nucleotide exchange factor (GEF) for Rac/Rop GTPase has been found in plants, termed PRONE-type GEF. We found eleven PRONE-type RacGEFs in rice, which may be involved in regulation of OsRac1 in innate immunity response. Recently, the PRONE-type GEF was found to interact with receptor-like protein kinase similar to R-proteins and PAMPs receptors such as Xa-21, Pi-d2, FLS2 and EFR, suggesting that the OsRacGEFs may regulate both PAMPs- and R protein-mediated disease resistance through activation of OsRac1 in rice.